In my Ruby-on-Rails database.yml file, I accidentally created a PostgreSQL database with a forward slash (/) in its name.
I have been unable to remove this database via psql commands, trying with various escape sequences.
Surround your database name in quotes:
DROP DATABASE "database/withslash";
From the Identifiers and Keywords documentation:
There is a second kind of identifier: the delimited identifier or quoted identifier. It is formed by enclosing an arbitrary sequence of characters in double-quotes ("). A delimited identifier is always an identifier, never a key word. So "select" could be used to refer to a column or table named "select", whereas an unquoted select would be taken as a key word and would therefore provoke a parse error when used where a table or column name is expected. The example can be written with quoted identifiers like this:
UPDATE "my_table" SET "a" = 5;
Quoted identifiers can contain any character, except the character with code zero.
Do note that quoted identifiers are case sensitive.
You cannot drop a database while connected to that database though, so maybe you want to use the command line dropdb command. Your shell will parse the quotes, so you want to escape the quotes:
dropdb \"database/withslash\"
Related
I am new to postgresql and just starting to use it. I am trying to load a file into a table and facing some issues.
Sample data - the file file1.RPT contains data in the below format
"Bharath"|Kumar|Krishnan
abc"|def|ghi
qwerty|asdfgh|lkjhg
Below is the load script that is used
LOAD CSV
INTO table1
....
WITH truncate,
fields optionally enclosed by '"',
fields escaped by '"'
fields terminated by '|'
....
However, the above script is not working and is not loading any data into the table. I am not sure whats the issue here. My understanding is that first row data has to be successfully loaded (since I have given optionally enclosed by) and the second row also must be loaded (since I am trying to escape the double quote).
Request help in getting the same rectified.
Thank you.
We cannot escape and optionally quote the same character. If the double-quote will be part of the data, then it can be ignored using field not enclosed option. The default option is field optionally enclosed by double-quote.
Apparently, you're not escaping the quote in the second row, because either you must use a backslash (or another quoting character) before:
abc\"|def|ghi
or you should enclose the entire line with quote
another alternative is to accept to have quotes in the first field, then you should use the following:
fields not enclosed
in your load script
I am running SQL queries using phpMYAdmin and getting syntax errors when entering single-quotes by keyboard.
When I use single-quotes entered by keyboard, as opposed to using phpMyAdmin auto-generated SQL statements, I get a syntax error. (Exactly the same SQL statement that works, no problem, from the auto-generated SQL statement)
The single-quotes look different when entered by keyboard then those that are auto-generated by phpMyAdmin.
As you can see in the image, the single-quotes for 'id', 'name' (quotes provided by phpMyAdmin's auto-generated code) are different than '3', 'Lawyers' (the type of single-quotes that show up when entered by keyboard).
Is this a bad setting on my laptop (Windows 10), or within phpMyAdmin?
How can I fix this?
The backticks (`) are used by MySQL to indicate database, table, and column names. Single quotes (') are used to indicate a string value. So the syntax used by phpMyAdmin is correct here. The trouble you're having with the SQL you're entering manually is because MySQL differentiates between the backtick and single quote; using the single quote for column names is incorrect here.
You can often omit the backtick entirely; it's needed specifically when the database/table/column name is also a MySQL keyword (date, for instance), and as you've seen can usually be left out entirely.
For further details and list of Keywords and Reserved Words in MySQL (v5.7) see 10.3 Keywords and Reserved Words in the MySQL documentation.
I've been working on an Express app that has a form designed to hold lines and quotes.
Some of the lines will have single quotes('), but overall it's able to store the info and I'm able to back it up and store it without any problems. Now, when I want do pg_dump and have the database put into an SQL file, the quotes seem to cause some things to appear a bit wonky in my text editor.
Would I have to create a method to change all the single quotation marks into double, or can I leave it as is and be able to upload it back to the database without causing major issues. I know people will continue to enter in lines that contain either single or double quotations, so I would like to know any solution or answer that would help greatly.
Single quotes in character data types are no problem at all. You just need to escape them properly in string literals.
To write data with INSERT you need to quote all string literals according to SQL syntax rules. There are tools to do that for you ...
Insert text with single quotes in PostgreSQL
However, pg_dump takes care of escaping automatically. The default mode produces text output to be re-imported with COPY (much faster than INSERT), and single quotes have no special meaning there. And in (non-default) csv mode, the default quote character is double-quote (") and configurable. The manual:
QUOTE
Specifies the quoting character to be used when a data value is quoted. The default is double-quote. This must be a single one-byte character. This option is allowed only when using CSV format.
The format is defined by rules for COPY and not by SQL syntax rules.
I can't seem to execute DROP USER username if the username contains hyphens (-), like for example user-name.
I tried a straightforward DROP USER user-name, also DROP USER 'user-name' but I'm getting: ERROR: syntax error at or near "'user-name'".
I would guess I need to use some kind of escaping or something.
Identifiers need to be quoted using double quotes, single quotes are for string literals:
DROP USER "user-name";
More details in the manual: http://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
My text file look like:
\home\stanley:123456789
c:/kobe:213
\tej\home\ant:222312
and create FOREIGN TABLE Steps:
CREATE FOREIGN TABLE file_check(txt text) SERVER file_server OPTIONS (format 'text', filename '/home/stanley/check.txt');
after select file_check (using: select * from file_check)
my console show me
homestanley:123456789
c:/kobe:213
ejhomeant:222312
Anyone can help me??
The file foreign-data-wrapper uses the same rules as COPY (presumably because it's the same code underneath). You've got to consider that backslash is an escape character...
http://www.postgresql.org/docs/9.2/static/sql-copy.html
Any other backslashed character that is not mentioned in the above table will be taken to represent itself. However, beware of adding backslashes unnecessarily, since that might accidentally produce a string matching the end-of-data marker (.) or the null string (\N by default). These strings will be recognized before any other backslash processing is done.
So you'll either need to double-up the backslashes or perhaps try it as a single-column csv file and see if that helps